annotate mercurial/help/internals/requirements.txt @ 29747:aba2bb2a6d0f

help: don't try to render a section on sub-topics

This patch subtly changes the behavior of the parsing of "X.Y" values
to not set the "section" variable when rendering a known sub-topic.
Previously, "section" would be the same as the sub-topic name. This
required the sub-topic RST to have a section named the same as the
sub-topic name.

When I made this change, the descriptions from help.internalstable
started being rendered in command line output. This didn't look correct
to me, as it didn't match the formatting of main help pages. I
corrected this by moving the top section to help.internalstable and
changing the section levels of all the "internals" topics.

The end result is that "internals" topics now match the rendering of
main topics on both the CLI and HTML. And, "internals" topics no longer
require a main section matching the name of the topic.

Repositories contain a file (``.hg/requires``) containing a list of
features/capabilities that are *required* for clients to interface
with the repository. This file has been present in Mercurial since
version 0.9.2 (released December 2006).

One of the first things clients do when opening a repository is read
``.hg/requires`` and verify that all listed requirements are supported,
aborting if not. Requirements are therefore a strong mechanism to
prevent incompatible clients from reading from unknown repository
formats or even corrupting them by writing to them.

Extensions may add requirements. When they do this, clients not running
an extension will be unable to read from repositories.

The following sections describe the requirements defined by the
Mercurial core distribution.

revlogv1
========

When present, revlogs are version 1 (RevlogNG). RevlogNG was introduced
in 2006. The ``revlogv1`` requirement has been enabled by default
since the ``requires`` file was introduced in Mercurial 0.9.2.

If this requirement is not present, version 0 revlogs are assumed.

store
=====

The *store* repository layout should be used.

This requirement has been enabled by default since the ``requires`` file
was introduced in Mercurial 0.9.2.

fncache
=======

The *fncache* repository layout should be used.

The *fncache* layout hash encodes filenames with long paths and
encodes reserved filenames.

This requirement is enabled by default when the *store* requirement is
enabled (which is the default behavior). It was introduced in Mercurial
1.1 (released December 2008).

shared
======

Denotes that the store for a repository is shared from another location
(defined by the ``.hg/sharedpath`` file).

This requirement is set when a repository is created via :hg:`share`.

The requirement was added in Mercurial 1.3 (released July 2009).

dotencode
=========

The *dotencode* repository layout should be used.

The *dotencode* layout encodes the first period or space in filenames
to prevent issues on OS X and Windows.

This requirement is enabled by default when the *store* requirement
is enabled (which is the default behavior). It was introduced in
Mercurial 1.7 (released November 2010).

parentdelta
===========

Denotes a revlog delta encoding format that was experimental and
replaced by *generaldelta*. It should not be seen in the wild because
it was never enabled by default.

This requirement was added in Mercurial 1.7 and removed in Mercurial
1.9.

generaldelta
============

Revlogs should be created with the *generaldelta* flag enabled. The
generaldelta flag will cause deltas to be encoded against a parent
revision instead of the previous revision in the revlog.

Support for this requirement was added in Mercurial 1.9 (released
July 2011). The requirement was disabled on new repositories by
default until Mercurial 3.7 (released February 2016).

manifestv2
==========

Denotes that version 2 of manifests are being used.

Support for this requirement was added in Mercurial 3.4 (released
May 2015). The requirement is currently experimental and is disabled
by default.

treemanifest
============

Denotes that tree manifests are being used. Tree manifests are
one manifest per directory (as opposed to a single flat manifest).

Support for this requirement was added in Mercurial 3.4 (released
August 2015). The requirement is currently experimental and is
disabled by default.